In facilities for animal care, e.g., zoological parks, research centers, and veterinary hospitals, occasions arise requiring isolation of animals from one another. Particularly when infectious disease or biohazards are involved, prolonged periods of confinement are essential since contact between different animals may lead to cross-contamination. Cages used for animal containment in zoological parks, veterinary hospitals, animal research facilities, and the like, traditionally comprise a square or rectangular floor with vertical bars defining side walls and a barred ceiling. Typically the prior art cages are small, box-like, and restrictive, thus, potentially compromising the psychosocial well-being and physiological responses of the caged animals.
In the case of non-human primates, particularly when very young, prolonged individual housing in small cages that do not afford visual access to conspecifics or offer opportunities for environmental control and recreation tend to result in a variety of abnormal patterns of behavior. The occurrence abnormal patterns of behavior can be used as an indicator of a lack of psychological well-being. The provision of environmental features that allow expression of the species typical activities has been shown to reduce the development or expression of abnormal patterns of behavior. Environments that provide opportunities for social interaction and environmental control appear to be most beneficial in promoting psychosocial well-being. Consequently, caregivers are often faced with abnormal primate behavior and developmental problems resulting from confinement in inadequate environments.
When non-human primates are subject to microbiological isolation in a conventional isolation cage for quarantine and the like, the problems are further augmented. To achieve isolation, commonly, the cage is placed in an isolation room or compartment which further limits contact with other animals and/or external stimuli.
Another problem with traditional caging systems relates to maintenance and sanitation. The maintenance process requires the caregiver to remove the confined animal from the cage to a holding cage for cleaning. Microbiological isolation adds further demands. In quarantine or isolation situations, it is undesirable for an animal to be subject to prolonged contact with the caregiver or other ambient biological influences during necessary activities such as cleaning and maintenance. This requires the animal to be transferred to a separate of holding cage through or in a "clean" room which must be scrupulously maintained. Additionally, this process requires the separate or holding cage to be microbiologically clean. Furthermore, depending on the nature of the disease, it may be necessary for the caregiver to maintain two separate cages exclusively for each animal to minimize the risk of communicating the biohazard agent from one animal to another via the "clean" room. Clearly, such activity constitutes an inefficient use of resources since the routine labor involved and facilities required unnecessarily burden the caregiving facility. Moreover, the process, itself, poses unnecessary risk of contamination from transferred contagions and infectious diseases.
Another problem common to traditional caging systems concerns access to the caged animal. In traditional caging systems, when handling the caged animal, it is often necessary for the caregiver to enter the cage or use adjuncts such as prods, dart guns, or capture nets. For handling of dangerous animals, such as lions, tigers, etc., the prior art teaches the use of squeeze-back type mechanisms such as that illustrated in U.S. Pat. No. 3,918,406. To minimize direct contact of the caregiver to the animal and to achieve the objective of handling the caged animal, U.S. Pat. No. 3,918,406 describes a system operated by an articulable lever assembly located outside the cage to move an entire side wall of the cage toward the opposite wall for "squeezing" the animal toward and through an opening. An easily accessible handle for operating the mechanism, may prove dangerous if improperly actuated by a confined animal, e.g., a primate. Furthermore, in the case of microbiological isolation and a sealed confinement chamber, such a structure may be impractical. It would be desirable to have a squeeze back device for handling the animal within the isolation cage and particularly providing a device which is 1) contained within the structure, 2) easy to manipulate and 3) does not present danger to the occupant animal.
With reference to danger to the animal, it is desirable in the animal containment discipline, to avoid use of machinery, equipment, power sources, and other adjuncts within a cage or which is accessible to the confined animal.